1. Field of the Invention
The present invention relates to a formulation for use in oral teeth, and more particularly relates to a formulation for propylaxising and treating dentin-associated diseases or symptoms.
2. Description of Associated Art
Dentin, which is also known as “dentine,” is a tissue constituting the tooth matrix, and located between dental enamel and dental pulp. Dentin is composed of 70% of inorganic substance, 20% of organic substance and 10% of water. The hardness of dentin is lower than that of dental enamel, but higher than that of cementum. Dentinal tubules throughout the dentin are arranged radially from the surface of the dental pulp towards the dental enamel. The dentinal tubules are wider at the ends near the dental pulp. The closer toward the surface the dentinal tubules with branches therebetween are, the narrower they are.
Common dentin-associated diseases or symptoms which cause pain, includes dental caries, tooth wearing, enamel loss and dentin hypersensitivity etc.
Dentin hypersensitivity is sometimes referred to as “tooth hypersensitivity” and “hypersensitive dentine.” Currently, various types of products or methods for relieving dentin hypersensitivity have been developed. However, up to now, none of the products or methods can provide rapid and long-term relieving effect.
Generally, the clinical methods for treating dentin hypersensitivity can fall into the following two categories: (1) chemical desensitizing method; and (2) physical desensitizing method.
As to the chemical desensitizing methods, corticosteroids were used in the early years to suppress inflammation. However, such methods are ineffective. Further, protein precipitation, which is also categorized as a chemical desensitizing method, utilizes a chemical agent to coagulate and denature the proteins in the dentinal tubule. For example, a formulation containing silver nitrate, phenol, formaldehyde or strontium chloride is used to denature collagen, and then forms precipitates which block the openings of the dentinal tubules. However, such formulation stimulates dental pulp and gingival, and the relapse rate is extremely high. Further, silver nitrate dyes teeth black permanently.
Moreover, chemical desensitizing methods also include a treating method for paralyzing pulp nerves. For example, some commercially available desensitizing toothpastes use potassium nitrate to suppress the excitation of pulp nerves. However, the clinical cases have shown that the pain on a patient cannot be relieved until the desensitizing toothpaste is persistently used for two weeks, and the therapeutic effect can last for only several months. That is to say, the methods for paralyzing pulp nerves cannot provide rapid and long-term therapeutic effects. Also, the long-term use of potassium nitrate leads to disorders associated to the paralysis of pulp nerves.
On the other hand, as to the physical desensitizing methods, for example, a sealant for dentinal tubules is used to directly seal the openings of dentinal tubules. The sealant includes, for example, resins, glass ionomer cements and or the like. For example, Jensen et al. (“A comparative study of two clinical techniques for treatment of root surface hypersensitivity,” Gen. Dent. 35:128-132.) proposed a method for directly sealing the openings of dentinal tubules using a resin-type dentin bonding agent. Although this method can immediately relive the pain caused by dentin hypersensitivity, it cannot provide long-term therapeutic effects. More specifically, the clinical cases have shown that, after a 6-months treatment, the resin-type bonding agent detaches significantly from the surfaces of teeth. As to the glass ionomer cements, Low et al. (“The treatment of hypersensitive cervical abrasion cavities using ASAP cement,” J. Oral Rehabil. 8(1):81-9) used glass ionomer cements to treat dentin hypersensitivity in 1981. Although glass ionomer cements can provide therapeutic effects, this type of material will be removed by constantly brushing the tooth. Further, Hansen et al. (“Dentin hypersensitivity treated with a fluoride-containing varnish or a light-curd glass ionomer liner,” Scand. J. Dent. Res. 100(6):305-9) used resin-enhanced glass ionomer cements to treat dentin hypersensitivity, but still no long-term therapeutic effects were achieved.
Accordingly, it is an urgent and important issue to provide rapid and prolonged effects to relieve dentin-associated symptoms and diseases.